One method for examining the gastrointestinal tract for the existence of polyps and other clinically relevant features that may provide an indication regarding the potential of cancer is performed by swallowing an imaging capsule that travels through the gastrointestinal tract and views the patient's situation from within. In a typical case the trip can take between 24-48 hours, after which the imaging capsule exits in the patient's feces. Typically the patient swallows a contrast agent to enhance the imaging ability of the imaging capsule. Then the patient swallows the imaging capsule to examine the gastrointestinal tract while flowing through the contrast agent. The imaging capsule typically includes a radiation source, for example including a radioisotope that emits X-rays and/or Gamma rays. The radiation typically may be collimated to allow it to be controllably directed toward a specific area during the imaging process. In an exemplary case the imaging capsule is designed to measure X-Ray fluorescence and/or Compton back-scattering and transmit the measurements (e.g. count rate, particle energy) to an external analysis device, for example an external transceiver worn by the patient and/or a computer or other dedicated instruments.
U.S. Pat. No. 7,787,926 dated Aug. 31, 2010 and U.S. Pat. No. 9,037,219 dated May 19, 2015 both by the current applicant, the disclosures of which are incorporated herein by reference, describe details related to the manufacture and use of such an imaging capsule.
It is desirable to minimize the amount of power required by the imaging capsule to successfully perform its trip through the gastrointestinal tract so that the size of a required power source can be reduced. Therefore it is desirable to optimize communications to reduce the amount of power required to communicate with the external transceiver.